As shown in FIG. 1, a data terminal equipment (DTE) 11 is connected to a media attachment unit (MAU) 12 through an AUI 13 in IEEE 802.3 Carrier Sense Multiple Access with Collision Detection (CSMA/CD) application. The AUI includes the connector and the transceiver cable for carrying encoded control and data signals between the physical signaling sub-layer of the DTE and the physical medium attachment sub-layer of the MAU and for providing duplex encoded data and control signals transmission. The MAU includes a physical medium attachment (PMA) which, via medium dependent interface (MDI), directly communicates with transmission media (coaxial cable). In PMA, there are hardware circuits with functions of signal transmission, receipt and collision detection. The PMA is also known as transceiver or tap in the technical field. The MAU operates to transmit the encoded data onto the coaxial cable, to receive the data coming through the coaxial cable, and to detect whether more than two DTEs intend to transmit information at the same time. The AUI often functions as a drop cable between the DTE and the transceiver. All signals in transceiver cable are differential which are driven by conventional differential drivers capable of driving a specified 78 .OMEGA. cable. A detailed description of the electronic characteristics of the AUI signals may be found in IEEE 802.3 specification.
Conventional differential driver circuits for driving the AUI signals are typically implemented in emitter coupled logic (ECL) circuitry which are complicated and suffers from large power consumption.
U.S. Pat. No. 5,309,036, however, discloses a driver circuit which is implemented in CMOS technology to attain a significantly lower power consumption.